Hi It is possible to get code or the exec for mod_i486-linux-MAXSEQ=10_MAXRES=1000_DOUBLE instead of the SINGLE mod_i486-linux-MAXSEQ=10_MAXRES=1000.Z Also I am cofused because it is a web page of a release5 but the link to the software is the one of number 4? Delmiro -- Dr. Delmiro Fernandez-Reyes National Institute for Medical Research Division of Mathematical Biology The Ridgeway, Mill Hill, London NW7 1AA Tel: +44 020 89593666 ext. 2632 Tel: +44 020 89138711 Direct Fax: +44 020 89138545 http://mathbio.nimr.mrc.ac.uk/